This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2000-020298, filed Jan. 28, 2000, the entire contents of which are incorporated herein by reference.
The present invention relates to an information writing device for writing desired information in disk-shaped information storage media such as magnetic disks.
A hard disk drive, as an example of an information storage apparatus provided with disk-shaped information storage media, comprises a casing in the form of an open-topped rectangular box and a top cover that is fastened to the casing by means of screws and closes a top opening of the casing.
The casing contains therein magnetic disks for use as information storage media, a spindle motor for supporting and rotating the magnetic disks, magnetic heads for writing in and reading information from the magnetic disks, a head actuator that supports the magnetic heads for movement with respect to the magnetic disks, a voice coil motor for rotating and positioning the head actuator, and a substrate unit including a head IC and the like. A printed-circuit board for controlling the respective operations of the spindle motor, voice coil motor, and magnetic heads is screwed to the outer surface of the bottom wall of the casing with the substrate unit between them.
The hard disk drive constructed in this manner is shipped after desired servo information is written in the magnetic disks after assembly. Normally, the servo information is written in the following manner. More specifically, a rotary positioner is mounted on the head actuator after the hard disk drive is assembled. The rotary positioner includes a rotating shaft coaxial with the rotating shaft of the head actuator and a push pin for pushing and rotating the head actuator. The push pin is pressed against a side face of the head actuator in a manner such that the magnetic disks are rotated at a given speed by means of the spindle motor of the hard disk drive as the rotary positioner is rotated for a given angle. By doing this, the head actuator is rotated so that magnetic heads are moved in the radial direction of the magnetic disks. In this state, predetermined servo information is written in the magnetic disks by means of the magnetic heads. Thereafter, the magnetic heads are successively moved to predetermined positions by means of the rotary positioner, and the servo information is written in regular sequence.
The following problems will be aroused, however, if the servo information is thus written in the magnetic disks that are incorporated in the hard disk drive. In general, a spindle motor of a hard disk drive uses a ball bearing, so that its shaft slight moves as it is driven. If the magnetic disks are rotated by means of this spindle motor as information writing operation is carried out, therefore, the movement of the motor shaft is inevitably recorded as deflection of tracks for servo information that is written in the magnetic disks. More specifically, the shaft movement of the spindle motor is not synchronous with the rotation of the magnetic disks, and the tracks for the written servo information fail to be perfectly circular.
Further, the engagement between the push pin of the rotary positioner and the head actuator is based only on the offset force of the head actuator and can be influenced by friction and sympathy between the push pin and the head actuator. It is difficult, therefore, to improve the positioning accuracy for the magnetic heads.
Thus, it is hard to write servo information accurately in the magnetic disks that are incorporated in the hard disk drive.
The present invention has been contrived in consideration of these circumstances, and its object is to provide an information writing device capable of accurately writing information in disk-shaped information storage media and a magnetic disk drive provided with magnetic disks loaded with servo information by means of the information writing device.
In order to achieve the above object, an information writing device according to the present invention comprises: a spindle motor; a disk loading hub detachably attached to a rotating shaft of the spindle motor, configured to be rotated by means of the spindle motor, and coaxially fitted with a plurality of disk-shaped storage media arranged at given spaces; a stacked head assembly including magnetic heads for writing information in the disk-shaped storage media mounted on the disk loading hub, the magnetic heads being as many as the storage media and arranged at given spaces from one another; a rotary positioner detachably supporting the stacked head assembly for rotating motion and capable of moving to and locating the magnetic heads of the stacked head assembly in predetermined positions over the disk-shaped storage media corresponding thereto; a plurality of ramps configured to load and unload the magnetic heads with respect to the disk-shaped storage media; and a moving mechanism configured to relatively move the spindle motor, rotary positioner, and ramps in a direction such that the distance between the rotating shaft of the spindle motor and the rotating shaft of the rotary positioner changes.
According to the information writing device constructed in this manner, the disk-shaped storage media are supported and rotated by using the dedicated spindle motor that is independent of a magnetic disk drive, and the information is written by means of the dedicated rotary positioner that supports the magnetic heads. Therefore, the information can be written in the storage media with higher accuracy than in the case where the information is written by means of the magnetic disk drive.
According to the information writing device described above, moreover, information can be simultaneously written in a large number of disk-shaped storage media, so that the processing efficiency can be improved considerably. The disk loading hub can be easily detached from the spindle motor by moving the rotary positioner and the ramps away from the motor. Further, information can be written in disk-shaped storage media of various sizes if the distance between the rotary positioner and the spindle motor is adjusted.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.